Automotive body panels have traditionally been made from mild steels. In an effort to decrease vehicle weight, aluminum alloy body panels have been increasing in popularity. The automotive and aerospace industries have focused primarily on the 5xxx and 6xxx series aluminum alloys, which are aluminum-magnesium and aluminum-magnesium-silicon alloys, respectively. The 5xxx and 6xxx series aluminum alloys may be shaped and processed by methods consistent with those of mild steel sheets. Aluminum-zinc alloys of the 7xxx series may achieve yield strengths similar to those of high strength steels, if they are age hardened. However, 7xxx series alloys may be received in a variety of tempers, some of which may be difficult to process and require further heat treatment before the age hardening process. For example, a 7xxx material received with a T6 temper may be difficult to draw or stretch at room temperature.